Anal glands

Anal glands

The anal glands or anal sacs are small, paired sacs located on either side of the anus between the external and internal sphincter muscles. Sebaceous glands within the lining secrete a foul smelling liquid that is used for identification of members within a species. These sacs are found in all carnivora except bearscite book | last = Dyce | first = K.M. | coauthors = Sack, W.O.; Wensing, C.J.G. | title = Textbook of Veterinary Anatomy | publisher = W.B. Saunders Company | date = 1987 | id = ISBN 0-7216-1332-2 ] and sea otters. [cite book | title=The Sea Otter in the Eastern Pacific Ocean | last=Kenyon |first=Karl W.
year=1969|publisher=U.S. Bureau of Sport Fisheries and Wildlife|location=Washington, D.C.


In dogs, these glands are occasionally referred to as "scent glands", because they enable the animals to mark their territory and identify other dogs. The glands can spontaneously empty, especially under times of stress, and create a very sudden unpleasant change in the odor of the dog. The anal glands normally empty when the dog defecates. Failure to empty results in discomfort from the full anal gland pushing on the anus. The glands can be emptied by the dog's keeper, or more typically by a groomer or veterinarian, by squeezing the gland so the contents are released through the small openings on either side of the anus. Discomfort is evidenced by the dog scooting its posterior on the ground, licking or biting at the anus, sitting uncomfortably, difficulty sitting or standing, or chasing its tail.

Discomfort may also be evident with impaction or infection of the anal glands. Anal gland impaction results from blockage of the duct leading from the gland to the opening. The gland is usually nonpainful and swollen. Anal gland infection results in pain, swelling, and sometimes abscessation and fever. Treatment is by expression of the gland, lancing of an abscess, and oral antibiotics and antibiotic infusion into the gland in the case of infection. The most common bacterial isolates from anal gland infection are "E. coli", "Enterococcus faecalis", "Clostridium perfringens", and "Proteus" species.cite book|author=Ettinger, Stephen J.;Feldman, Edward C.|title=Textbook of Veterinary Internal Medicine|edition=4th ed.|publisher=W.B. Saunders Company|year=1995|id=ISBN 0-7216-6795-3]

Anal glands may be removed surgically in a procedure known as anal sacculectomy. This is usually done in the case of recurrent infection or because of the presence of an anal sac adenocarcinoma, a malignant tumor. Potential complications include fecal incontinence (especially when both glands are removed), tenesmus from stricture or scar formation, and persistent draining fistulae.cite journal|author=Hill, Lawrence M.; Smeak, Daniel D.|title=Open versus closed bilateral anal sacculectomy for treatment of non-neoplastic anal sac disease in dogs: 95 cases (1969–1994)|journal=Journal of the American Veterinary Medical Association|year=2002|volume=221|issue=5|pages=662–665|url=|accessdate=2006-08-31|doi=10.2460/javma.2002.221.662|format=abstract]

Anal gland fluid is normally yellow to tan in color and watery in consistency. Impacted anal gland material is usually brown or gray and thick. The presence of blood or pus indicates infection.


Opossums use their anal glands when they "". As the opossum mimics death, the glands secrete a foul-smelling liquid, suggesting the opossum is rotting. Note that opossums are not members of the carnivora, and that their anal sacs differ from those of dogs and their relatives.


Skunks use their anal glands to spray a foul-smelling and sticky fluid as a defense against predators.


Research by the Institute for Pheromone Research and the Department of Chemistry, Indiana University suggests that weasels may well use their anal glands in gender recognition. [Zhang JX et al. "Putative chemosignals of the ferret (Mustela furo) associated with individual and gender recognition." [ PubMed]
Zhang JX et al. "Possible coding for recognition of sexes, individuals and species in anal gland volatiles of Mustela eversmanni and M. sibirica." [ PubMed]

ee also

*Anal sac adenocarcinoma


External links

* [ Anal Sacs from The Pet Health Library]
* [ All about a dog's anal sacs]
* [ Understanding about a dog's anal glands]
* [ How to express a dog's anal glands]

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • anal glands — circumanal g s …   Medical dictionary

  • Anal fistula — DiseaseDisorder infobox Name = Anal fistula ICD10 = ICD10|K|60|3|k|55 ICD9 = ICD9|565.1 An anal fistula is an abnormal connection between the epithelialised surface of the anal canal and (usually) the perianal skin.Anal fistulae originate from… …   Wikipedia

  • Anal columns — Coronal section of rectum and anal canal. The interior of the anal cami and lower …   Wikipedia

  • Anal — A nal, a. [From {Anus}.] (Anat.) Pertaining to, or situated near, the anus; as, the anal fin or glands. [1913 Webster] …   The Collaborative International Dictionary of English

  • anal canal — End portion of the alimentary canal, distinguished from the rectum by the transition from an internal mucous membrane layer to one of skinlike tissue and by its narrower diameter. Waste products move from the rectum to the anal canal. The human… …   Universalium

  • Anal sex — This article is about the human sexual act. For anal sex in non human animals, see Animal sexual behaviour. Depiction of anal sex on 510 BC Attic red figure …   Wikipedia

  • anal sac — in carnivores, either of two sacs found between the internal and external anal sphincters, lined with sebaceous glands and in some species with apocrine glands …   Medical dictionary

  • anal gland — noun : any of numerous glands, occurring solitary or in pairs or groups, near the anus and sometimes opening into the rectum: as a. : either of the paired glands of a skunk that produce an offensive secretion b. : a gland in mollusks of the genus …   Useful english dictionary

  • pygidial glands — (ARTHROPODA: Insecta) 1. In Coleoptera, paired organs opening beneath the last abdominal tergite that function to secrete a corrosive, pungent defense fluid, or a substance that lowers surface tension of the water to increase propulsion; also… …   Dictionary of invertebrate zoology

  • Brunner's glands — Section of duodenum. (Duodenal glands in submucosa labeled at right, fourth from the top.) Latin glandulae duodenales Gray s …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”